Thus presently available systems dispense oil from a central tank by way of a pump and a number of meters disposed at each dispensing station or location. Unfortunately meters and associated joints are susceptible to leaks and a plurality of meters even more so. The meter at a dispensing station is set to zero by the user before oil is drawn off and the quantity dispensed noted by the user. Unfortunately there is no check available on the quantity of oil delivered and so the system is open to abuse. That is, not all the oil dispensed finds its way to customer's cars. While oil remained relatively cheap, pilfering was on a fairly small scale and losses to the garage proprietor were insignificant. Now, however, the situation has changed somewhat.
The meters in present use in retail outlets must have in the United Kingdom Board of Trade approval to protect customers and to ensure accuracy. Satisfactory meters are relatively large and heavy and come essentially in two kinds. Firstly, there are the wall-mounted meters which are the larger of the two kinds. These must be mounted on a secure structure and supplied with oil lines from the pump and to the delivery hose. It has a large meter dial which can be set to zero and which can be seen from some distance off.
Secondly there are the hose-end meters. Although much smaller they are still quite bulky and require a certain amount of manipulation in order to render them in a position where the dial can be reset and read. Nevertheless they are at the point of application of oil and so are often preferred to wall mounted meters. However, the meters disposed at the end of the hose tend to suffer from maltreatment and so the problem of leaks increases. Moreover, because of the weight and bulk of even these smaller meters it is necessary to employ reeled, thick-walled, spirally-wound double wire insert rubber hose which increases the overall bulkiness of the arrangement.
In any event, although the meters are accurate, their analogue dials often provide an inaccurate read-out so that there may occur an error in any but the largest quantities dispensed in the order of about 5%. Thus it is often not permitted to dispense less than a preset minimum quantity of oil in order to keep the error as small as possible.
Furthermore, although the systems used hitherto are satisfactory in most respects, except as mentioned above, the provision of a meter at each dispensing station is space consuming and more importantly, expensive.
It is an object of this invention to provide a liquid dispensing system of the type referred to which alleviates at least some of the problems referred to above.